20111171057 has 2 divisors, whose sum is σ = 20111171058. Its totient is φ = 20111171056.

The previous prime is 20111171051. The next prime is 20111171099. The reversal of 20111171057 is 75017111102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19932921856 + 178249201 = 141184^2 + 13351^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20111171057 is a prime.

It is not a weakly prime, because it can be changed into another prime (20111171051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055585528 + 10055585529.

It is an arithmetic number, because the mean of its divisors is an integer number (10055585529).

Almost surely, 2^20111171057 is an apocalyptic number.

It is an amenable number.

20111171057 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111171057 is an equidigital number, since it uses as much as digits as its factorization.

20111171057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 490, while the sum is 26.

Adding to 20111171057 its reverse (75017111102), we get a palindrome (95128282159).

The spelling of 20111171057 in words is "twenty billion, one hundred eleven million, one hundred seventy-one thousand, fifty-seven".